Small is dangerous

My much-publicised call for regulation to catch up with innovation in the field of nanotechnology - and especially the use of nanoparticles of titanium dioxide in those sunscreens and other cosmetic products that are already commercially available - has been slightly overshadowed by discussions about my personal scientific credentials.

By quoting my assertion that "the laws of physics do not apply at the molecular level" outside the context of the words that followed it - "quantum physics kicks in" - your article misses the point of my argument (21 June, p 10). I had hoped it would be obvious that I meant to draw a distinction between classical or Newtonian and quantum physics to explain to a lay audience how different sized particles of an equivalent material can exhibit different properties.

I wish nothing more than to facilitate reasoned dialogue between scientists, industry, policy makers and the public on ...

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